Broadband Ultraviolet Photodetector Based on Graphene/β-Ga<sub>2</sub>O<sub>3</sub>/GaN Heterojunction

Abstract

Broadband ultraviolet (BUV) photodetectors are widely used in military and civil fields. A high performance BUV photodetector based on graphene/β-Ga2O3/GaN heterojunction is proposed and realized by semiconductor micro-fabrication techniques in this paper. The β-Ga2O3 and GaN films are grown by metal organic chemical vapor deposition (MOCVD), and the graphene is also used as a transparent electrode. The device exhibits a broad response band from 230 nm to 368 nm with responsivity exceeding 0.4A/W at -5 V bias voltage and a peak responsivity of 0.53 A/W at 256 nm. These performances can be attributed to the internal gain mechanism of graphene/β-Ga2O3/GaN heterojunction and the optical properties of graphene. Our work provides an efficient method to realize a high-performance BUV photodetector for photoelectric applications.